NORTH CAROLINA — A strong El Niño is developing in the Pacific Ocean and is likely to affect North Carolina’s weather over the next few months. Past strong El Niño winters have usually brought above-average rainfall and slightly warmer temperatures to the state. Snowfall during those winters has been mixed, with big totals in some years and almost none in others. While the pattern may turn more active, there is no reason to panic.
What Is El Niño
El Niño is a natural climate pattern marked by warmer-than-normal sea surface temperatures in the central and eastern tropical Pacific Ocean. It is the “warm phase” of a larger cycle called the El Niño-Southern Oscillation, or ENSO. Even though it happens in the Pacific, it can shift jet streams and weather patterns around the world.
Under normal conditions, strong trade winds blow from east to west along the equator. Those winds push warm water toward Asia and Australia and allow cooler water to rise along South America. During El Niño, the trade winds weaken and stall, letting the Pacific warm up.
One of the Strongest on Record
This year’s El Niño is already underway, with the equatorial Pacific running well above average. It could become one of the strongest El Niño events on record. That extra ocean heat helps fuel an active subtropical jet stream across the southern United States.
One benefit is that El Niño tends to reduce hurricane activity in the Atlantic. The downside is that it can lead to more nor’easters along the East Coast. Some of that more active pattern has already been showing up this fall.
Raleigh Rainfall Runs Above Normal in Most Strong Years
Past strong El Niño winters have often been wet in Raleigh. The 1997-1998 winter brought 16.03 inches of rain from December through February, about 6.23 inches above normal. The 2015-2016 winter delivered 14.28 inches, while 1982-1983 brought 13.18 inches…